BacterioFiles 411 - Parasite Produces Partial Plant-like Predator

A choanoflagellate
By Daniel Stoupin
CC BY-SA 3.0

This episode: Giant virus in newly discovered microscopic marine predator encodes several light-harvesting proteins!

Download Episode (7.8 MB, 11.4 minutes)

Show notes:
Microbe of the episode: Dolphin mastadenovirus A

News item

Takeaways
Giant viruses are distinct in many ways from other viruses, even aside from their size. One way is the large number and variety of genes they carry in their genome. Though many of their genes are unknown in origin and function, many others appear to take the place of essential reproductive functions, such as translation and protein synthesis. This allows them to assume more control of their host's metabolism and control its resources more optimally.

In this study, the sequence of a giant virus was discovered seemingly infecting a newly discovered microscopic marine predator. The eukaryotic cell feeds on smaller microbes such as bacteria, but strangely, the virus carries genes for several light-harvesting proteins, possibly converting a heterotrophic predator into a partial phototroph.

Journal Paper:
Needham DM, Yoshizawa S, Hosaka T, Poirier C, Choi CJ, Hehenberger E, Irwin NAT, Wilken S, Yung C-M, Bachy C, Kurihara R, Nakajima Y, Kojima K, Kimura-Someya T, Leonard G, Malmstrom RR, Mende DR, Olson DK, Sudo Y, Sudek S, Richards TA, DeLong EF, Keeling PJ, Santoro AE, Shirouzu M, Iwasaki W, Worden AZ. 2019. A distinct lineage of giant viruses brings a rhodopsin photosystem to unicellular marine predators. Proc Natl Acad Sci 116:20574–20583.

Other interesting stories:

• Deep-sea mussels collect multiple symbiont microbes to use best one for current environment
• Microscopic water droplets help bacteria survive on dry leaves

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

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BacterioFiles 410 - Microbes Modify Muscle Measurement

A laboratory mouse

This episode: Mice that got a microbe transplant from humans with higher physical function performed better in certain ways than mice receiving microbes from humans with lower physical function!

Download Episode (6.7 MB, 9.8 minutes)

Show notes:
Microbe of the episode: Stenotrophomonas maltophila

News item

Takeaways
Our bodies and our microbe communities are closely interconnected, with effects going both ways. Studies had previously shown that making changes to the microbe communities of mice could even affect the physical function and body composition of the mice.

This study aimed at addressing the same question in humans. There were certain consistent differences in microbial communities between elderly people with high ability to function physically, compared with low functioning people. These differences carried over in transplants of microbes from people to mice, and mice receiving microbes from high-functioning humans did better in tests of grip strength than mice receiving microbes from low-functioning people.

Journal Paper:
Fielding RA, Reeves AR, Jasuja R, Liu C, Barrett BB, Lustgarten MS. 2019. Muscle strength is increased in mice that are colonized with microbiota from high-functioning older adults. Exp Gerontol 127:110722.

Other interesting stories:

• Engineering better viruses for phage therapy
• Using staph bacteria to clean up metal-polluted environments (paper)

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.

Interview of me on the podcast Curioscity

Another good podcast you should check out is Curioscity, in which the host, Calvin Yeager, interviews other scientists about various aspects of science, their research, and other aspects of how science gets done!

He recently interviewed me about my experience getting a job as a scientist outside academia, and what that's like, so if you'd like to hear about that, here's the link:

Curioscity 53 - What Is Industry?

BacterioFiles 409 - Marine Methane Mostly Munched

Methanococcus species
By Anne Fjellbirkeland,
from PLoS Biol 2004:e358
CC BY 2.5

This episode: Microbes in low-oxygen zones in the ocean consume significant amounts of methane anaerobically!

Download Episode (5.2 MB, 7.6 minutes)

Show notes:
Microbe of the episode: Mojiang henipavirus

News item

Takeaways
Methane is a much more potent greenhouse gas than carbon dioxide. Fortunately there's not as much of it in the atmosphere, but even smaller amounts can have significant effects on the climate.

One source of methane is low-oxygen zones in the ocean, where certain kinds of archaea make methane as part of their energy metabolism. This study found that other anaerobic microbes in the same areas consume much of this methane, preventing it from reaching the atmosphere.

Journal Paper:
Thamdrup B, Steinsdóttir HGR, Bertagnolli AD, Padilla CC, Patin NV, Garcia‐Robledo E, Bristow LA, Stewart FJ. 2019. Anaerobic methane oxidation is an important sink for methane in the ocean’s largest oxygen minimum zone. Limnol Oceanogr 64:2569–2585.

Other interesting stories:

• Correlated microbiome metabolites with compounds in blood of twins (paper)
• Bacteria inhibit soil fungi via airborne chemicals (paper)

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.

BacterioFiles 408 - Currents Carry Cloud Creators

Snowflake
By Alexey Kljatov, CC BY-SA 4.0

This episode: Ocean bacteria brought up from the sea floor into the air can help create clouds!

Download Episode (6.1 MB, 8.9 minutes)

Show notes:
Microbe of the episode: Streptomyces thermodiastaticus

News item

Takeaways
The ocean is an important player affecting the climate of the planet, in many ways. Its effects on clouds influence the amount of solar radiation reflected back into space or trapped as heat, and microbes play a role in this effect. Certain microbes make particles that form the nucleus of water droplets or ice crystals that make up clouds, and other microbes can perform this nucleation themselves.

In this study, an unusual combination of a phytoplankton bloom and strong winds and currents, all in the right places, led to a large number of ice-nucleating bacteria being fed and then brought up from the sea floor and launched into the air, possibly affecting weather patterns in the Arctic.

Journal Paper:
Creamean JM, Cross JN, Pickart R, McRaven L, Lin P, Pacini A, Hanlon R, Schmale DG, Ceniceros J, Aydell T, Colombi N, Bolger E, DeMott PJ. 2019. Ice Nucleating Particles Carried From Below a Phytoplankton Bloom to the Arctic Atmosphere. Geophys Res Lett 46:8572–8581.

Other interesting stories:

• Bacterial immune system (CRISPR/Cas) could save bananas from fungus that wipes them out
• Potentially useful antibiotic produced by gut microbe (paper)

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.

BacterioFiles 407 - Fungus Facilitates Phototroph Feeding

Various Phomopsis fungi

Probably the last episode of the year. See you in the next!

This episode: Fungus living inside plants helps them form partnerships with nitrogen-fixing bacteria!

Download Episode (5.9 MB, 8.5 minutes)

Show notes:
Microbe of the episode: Prevotella intermedia

Takeaways
Plants are very good at acquiring carbon, but they can often use some help with other nutrients. Many form partnerships with microbes such as nitrogen-fixing bacteria or mycorrhizal fungi that can help gather nutrients from the soil better than the plants' own roots.

In this study, legume plants could form a partnership with nitrogen-fixing bacteria in its roots, but a fungus living inside the plant could enhance this partnership even more, increasing the amount of nitrogen acquired and influencing the community of microbes around the plant roots in ways favorable to all partners.

Journal Paper:
Xie X-G, Zhang F-M, Yang T, Chen Y, Li X-G, Dai C-C. 2019. Endophytic Fungus Drives Nodulation and N₂ Fixation Attributable to Specific Root Exudates. mBio 10:e00728-19, /mbio/10/4/mBio.00728-19.atom.

Other interesting stories:

• Diet could affect antibiotic impact on the gut microbiome
• Feeding gut microbes particular preferred foods can manipulate the community structure

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.

BacterioFiles 406 - Different DNA Destroys Disease Drivers

Neisseria gonorrhoeae colonies on agar
By Xishan01, CC BY-SA 3.0

This episode: DNA from related species can kill certain pathogens when they incorporate it into their genome!

Download Episode (7.9 MB, 11.5 minutes)

Show notes:
Microbe of the episode: Ungulate tetraparvovirus 3

Paper summary (paywall)

Takeaways
Neisseria gonorrhoeae, the bacteria that cause gonorrhea, have the unusual ability of taking up DNA from their surroundings at any time and making use of it in their own genome. This helps them acquire useful traits that help them survive better, such as antibiotic resistance. But it turns out that the ability is also a secret weakness!

This study showed that when N. gonorrhoeae takes up DNA from harmless, commensal species of Neisseria in the body, the DNA is similar enough to be incorporated into the genome but different enough that it kills the pathogen. This effect also occurs with a serious pathogen in the same genus, N. meningitidis.

Journal Paper:
Kim WJ, Higashi D, Goytia M, Rendón MA, Pilligua-Lucas M, Bronnimann M, McLean JA, Duncan J, Trees D, Jerse AE, So M. 2019. Commensal Neisseria Kill Neisseria gonorrhoeae through a DNA-Dependent Mechanism. Cell Host Microbe 26:228-239.e8.

Other interesting stories:

• Kombucha could be good model system for studying microbial cooperation
• Antidepressants can modify bacterial metabolism of serotonin in the gut

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.